Anodal transcranial direct current stimulation of parietal cortex enhances action naming in Corticobasal Syndrome

Abstract

Background: Corticobasal Syndrome (CBS) is a neurodegenerative disorder that overlaps both clinically and neuropathologically with Frontotemporal dementia (FTD) and is characterized by apraxia, alien limb phenomena, cortical sensory loss, cognitive impairment, behavioral changes and aphasia. It has been recently demonstrated that transcranial direct current stimulation (tDCS) improves naming in healthy subjects and in subjects with language deficits.Objective: The aim of the present study was to explore the extent to which anodal tDCS over the parietal cortex (PARC) could facilitate naming performance in CBS subjects.Methods: Anodal tDCS was applied to the left and right PARC during object and action naming in seventeen patients with a diagnosis of possible CBS. Participants underwent two sessions of anodal tDCS (left and right) and one session of placebo tDCS. Vocal responses were recorded and analyzed for accuracy and vocal Reaction Times (vRTs).Results: A shortening of naming latency for actions was observed only after active anodal stimulation over the left PARC, as compared to placebo and right stimulations. No effects have been reported for accuracy.Conclusions: Our preliminary finding demonstrated that tDCS decreased vocal reaction time during action naming in a sample of patients with CBS. A possible explanation of our results is that anodal tDCS over the left PARC effects the brain network implicated in action observation and representation. Further studies, based on larger patient samples, should be conducted to investigate the usefulness of tDCS as an additional treatment of linguistic deficits in CBS patients.

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016

“…We identified 15 studies that evaluated the effects of tDCS on patients with Alzheimer’s disease [111], [112], [113], [114], [115], [116], Parkinson’s Disease [109], [117], [118], [119], [120], [121], Dementia with Lewy Bodies [122], Corticobasal degeneration [123], and Frontotemporal dementia [124]. In all, there were over 275 patients (some assigned to sham conditions) who received between 7 and 30 minutes of stimulation in each of 1 to 10 sessions with an intensity of between 1 and 2.8 mA.…”

Electrical brain stimulation in different variants of primary progressive aphasia: A randomized clinical trial

“…Although studies [13,[16][17][18][19][20][21] provide proof-of-concept for the efficacy of tDCS in PPA, these small studies do not yet provide sufficient evidence for sustainability of gains and generalization to untreated items. One difficulty in studying tDCS efficacy in PPA is its phenotypic diversity.…”

Non-Invasive Brain Stimulation in Dementia: A Complex Network Story

“…Their findings showed that a single session over the DLPFC was sufficient to strengthen episodic memory up to 1 month, relative to sham stimulation [95]. Similarly, DLPFC modulation showed beneficial memory effects in mild cognitive impairment (MCI) patients [97, 98], although these positive effects were obtained using different stimulation protocols (i.e., 10 excitatory sessions vs. 1 inhibitory session).…”

“…Manenti et al [95] investigated the effect of atDCS on the DLPFC in individuals with subjective memory complaints, a condition at greater risk of AD [116]. Their findings showed that a single session over the DLPFC was sufficient to strengthen episodic memory up to 1 month, relative to sham stimulation [95].…”